Cytoplasmic and secreted Saccharomyces cerevisiae invertase mRNAs encoded by one gene can be differentially or coordinately regulated

1984 ◽  
Vol 4 (9) ◽  
pp. 1682-1688
Author(s):  
D Perlman ◽  
P Raney ◽  
H O Halvorson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Heat Shock ◽  
De Novo ◽  
Signal Sequence ◽  
Hormone Treatment ◽  
Mrna Levels ◽  
Secretion Signal ◽  
Cycle Arrest ◽  
De Novo Protein Synthesis

A single structural gene, SUC2, encodes both secreted and cytoplasmic invertase in Saccharomyces cerevisiae. It is known that the unprocessed polypeptides which differ by a secretion signal sequence are encoded by separate mRNAs. This unusual transcriptional organization raises the question as to the degree to which the transcripts can be independently regulated. To define a system for studying this problem, we examined invertase transcription after various physiological perturbations of cells: rapid catabolite derepression, heat shock, and cell cycle arrest. With each treatment, fluctuations in mRNA levels for both cytoplasmic and secreted invertase were observed. We concluded that (i) catabolite-derepressed synthesis of the mRNAs occurs rapidly after a drop in glucose, is a sustained response, and does not require de novo protein synthesis; (ii) heat shock transcription of both invertase mRNAs is, in contrast, a brief and transient response requiring de novo protein synthesis; and (iii) alpha-mating hormone treatment (G1 phase arrest and release) results in regular and coordinated synthesis of both mRNAs midway between rounds of histone mRNA synthesis. We propose that invertase mRNA regulation involves constitutively synthesized transcriptional factors (observed during catabolite derepression) and transient factors (observed during heat shock and possibly during synchronous growth). Moreover, the mRNA levels for secreted and cytoplasmic invertase can be independently regulated.

scholarly journals Cytoplasmic and secreted Saccharomyces cerevisiae invertase mRNAs encoded by one gene can be differentially or coordinately regulated.

1984 ◽  
Vol 4 (9) ◽  
pp. 1682-1688 ◽  
Author(s):  
D Perlman ◽  
P Raney ◽  
H O Halvorson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Synthesis ◽  
Heat Shock ◽  
De Novo ◽  
Signal Sequence ◽  
Hormone Treatment ◽  
Mrna Levels ◽  
Secretion Signal ◽  
Cycle Arrest ◽  
De Novo Protein Synthesis

A single structural gene, SUC2, encodes both secreted and cytoplasmic invertase in Saccharomyces cerevisiae. It is known that the unprocessed polypeptides which differ by a secretion signal sequence are encoded by separate mRNAs. This unusual transcriptional organization raises the question as to the degree to which the transcripts can be independently regulated. To define a system for studying this problem, we examined invertase transcription after various physiological perturbations of cells: rapid catabolite derepression, heat shock, and cell cycle arrest. With each treatment, fluctuations in mRNA levels for both cytoplasmic and secreted invertase were observed. We concluded that (i) catabolite-derepressed synthesis of the mRNAs occurs rapidly after a drop in glucose, is a sustained response, and does not require de novo protein synthesis; (ii) heat shock transcription of both invertase mRNAs is, in contrast, a brief and transient response requiring de novo protein synthesis; and (iii) alpha-mating hormone treatment (G1 phase arrest and release) results in regular and coordinated synthesis of both mRNAs midway between rounds of histone mRNA synthesis. We propose that invertase mRNA regulation involves constitutively synthesized transcriptional factors (observed during catabolite derepression) and transient factors (observed during heat shock and possibly during synchronous growth). Moreover, the mRNA levels for secreted and cytoplasmic invertase can be independently regulated.

Changes in methionine adenosyltransferase during liver regeneration in the rat

1998 ◽  
Vol 275 (1) ◽  
pp. G14-G21 ◽  
Author(s):  
Zong-Zhi Huang ◽  
Zebin Mao ◽  
Jiaxin Cai ◽  
Shelly C. Lu
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Protein Synthesis ◽  
De Novo ◽  
Mrna Level ◽  
Methionine Adenosyltransferase ◽  
Mrna Levels ◽  
Mrna Stabilization ◽  
De Novo Protein Synthesis ◽  
Mat Gene

Liver-specific and non-liver-specific methionine adenosyltransferase (MAT) are products of two genes (MAT1A and MAT2A, respectively) that catalyze the formation of S-adenosylmethionine (SAM), the principal methyl donor. We previously showed that MAT2A expression was associated with more rapid cell growth. Here we examined changes in hepatic MAT gene expression and related consequences after two-thirds partial hepatectomy (PH) in rats. The mRNA levels of both MAT forms increased from 3 to 6 h, but the MAT1A level then fell below baseline from 12 to 24 h, whereas the MAT2A level remained elevated up to 4 days after PH. The increase in the MAT2A mRNA level was due to increased gene transcription and mRNA stabilization. The change in the MAT1A mRNA level was posttranscriptional and did not require de novo protein synthesis. Changes in MAT activity were consistent with an increased amount of MAT isozymes. SAM levels, the ratio of SAM to S-adenosylhomocysteine (SAH), and DNA methylation fell from 6 to 24 h, whereas SAH levels increased slightly at 12 and 24 h after PH. Both increased SAM utilization and MAT2A gene expression likely contributed to the fall in SAM.

Heat Shock Induces Barotolerance in Listeria monocytogenes

2008 ◽  
Vol 71 (2) ◽  
pp. 426-430 ◽  
Author(s):  
MELINDA M. HAYMAN ◽  
RAMASWAMY C. ANANTHESWARAN ◽  
STEPHEN J. KNABEL
Keyword(s):  
High Pressure ◽  
Protein Synthesis ◽  
Listeria Monocytogenes ◽  
Heat Shock ◽  
Protective Effect ◽  
De Novo ◽  
High Pressure Processing ◽  
Milk Samples ◽  
Ultrahigh Temperature ◽  
De Novo Protein Synthesis

The aim of this study was to investigate the effect of heat shock on the resistance of Listeria monocytogenes to high pressure processing (HPP). L. monocytogenes ATCC 19115 was grown to stationary phase at 15°C and inoculated into whole ultrahigh-temperature milk at ~107 CFU/ml. Milk samples (5 ml) were placed into plastic transfer pipettes, which were heat sealed and then heated in a water bath at 48°C for 10 min. Immediately after heat shock, the milk was cooled in water (20°C) for 25 min and then placed on ice. The samples were high pressure processed at ambient temperature (~23°C) at 400 MPa for various times up to 150 s. Following HPP, the samples were spread plated on tryptic soy agar supplemented with yeast extract. Heat shock significantly increased the D400 MPa-value of L. monocytogenes from 35 s in non–heat-shocked cells to 127 s in heat-shocked cells (P < 0.05). Addition of chloramphenicol before heat shock eliminated the protective effect of heat shock (P < 0.05). Heat shock for 5, 10, 15, or 30 min at 48°C resulted in maximal barotolerance (P < 0.05); increasing the time to 60 min significantly decreased survival compared with that at 5, 10, 15, or 30 min (P < 0.05). These results indicate that prior heat shock significantly increases the barotolerance of L. monocytogenes and that de novo protein synthesis during heat shock is required for this enhanced barotolerance.

Regulation by retinoic acid of acylation-stimulating protein and complement C3 in human adipocytes

2001 ◽  
Vol 356 (2) ◽  
pp. 445-452 ◽  
Author(s):  
Thea SCANTLEBURY ◽  
Allan D. SNIDERMAN ◽  
Katherine CIANFLONE
Keyword(s):  
Protein Synthesis ◽  
Retinoic Acid ◽  
De Novo ◽  
Complement C3 ◽  
Mrna Levels ◽  
Triacylglycerol Synthesis ◽  
Acylation Stimulating Protein ◽  
C3 Gene ◽  
De Novo Protein Synthesis ◽  
Stimulation Of

Acylation-stimulating protein (ASP), a product of complement C3, stimulates triacylglycerol synthesis in adipocytes. Previous studies have identified transthyretin, associated with chylomicrons, as a stimulator of C3 and ASP production. Since both transthyretin and chylomicrons transport retinyl ester/retinol, our goal was to investigate whether retinoic acid (RA) could be a potential hormonal mediator of the effect. Inhibitors of protein synthesis and protein secretion eliminated the stimulatory effects of chylomicrons on both C3 and ASP production in human differentiated adipocytes, suggesting that de novo protein synthesis and secretion are both required. Incubation with chylomicrons increased C3 mRNA levels (37±1.5%). RA alone or with chylomicrons had a stimulatory effect on C3 production (29-fold at 16.6nM RA) and ASP production. An RA receptor antagonist blocked stimulation of C3 mRNA and C3 secretion by both RA and chylomicrons. Finally, RA and chylomicrons activated a 1.8kb C3-promoter–luciferase construct transfected into 3T3-F442 and 3T3-L1 cells (by 41±0.2% and 69±0.3% respectively), possibly via RA receptor half-sites identified by sequence analysis. This is the first evidence documenting stimulation by RA of the C3 gene. Thus we propose RA as a novel cellular trigger in chylomicrons that subsequently results in increased ASP production by adipocytes after a meal.

scholarly journals Viral Gene Expression Patterns in Human Herpesvirus 6B-Infected T Cells

2002 ◽  
Vol 76 (15) ◽  
pp. 7578-7586 ◽  
Author(s):  
Bodil Øster ◽  
Per Höllsberg
Keyword(s):  
Gene Expression ◽  
T Cells ◽  
Protein Synthesis ◽  
De Novo ◽  
Expression Patterns ◽  
Human Herpesvirus ◽  
Viral Gene Expression ◽  
Polymerase Activity ◽  
Viral Gene ◽  
De Novo Protein Synthesis

ABSTRACT Herpesvirus gene expression is divided into immediate-early (IE) or α genes, early (E) or β genes, and late (L) or γ genes on the basis of temporal expression and dependency on other gene products. By using real-time PCR, we have investigated the expression of 35 human herpesvirus 6B (HHV-6B) genes in T cells infected by strain PL-1. Kinetic analysis and dependency on de novo protein synthesis and viral DNA polymerase activity suggest that the HHV-6B genes segregate into six separate kinetic groups. The genes expressed early (groups I and II) and late (groups V and VI) corresponded well with IE and L genes, whereas the intermediate groups III and IV contained E and L genes. Although HHV-6B has characteristics similar to those of other roseoloviruses in its overall gene regulation, we detected three B-variant-specific IE genes. Moreover, genes that were independent of de novo protein synthesis clustered in an area of the viral genome that has the lowest identity to the HHV-6A variant. The organization of IE genes in an area of the genome that differs from that of HHV-6A underscores the distinct differences between HHV-6B and HHV-6A and may provide a basis for further molecular and immunological analyses to elucidate their different biological behaviors.

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